METHOD AND SYSTEM OF USING A LOCAL HOSTED CACHE AND CRYPTOGRAPHIC HASH FUNCTIONS TO REDUCE NETWORK TRAFFIC

• US 20090319473A1
• Filed: 06/19/2008
• Published: 12/24/2009
• Est. Priority Date: 06/19/2008
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Nusca, Gianluigi, Zuberi, Khawar Mahmood, Narkhede, Kushal, Tan, See-Mong, Shah, Nilesh R., Singhal, Sandeep K., Rao, Ravi T., Flannery, Eliot John, Briggs, R. Scott
• Granted Patent: US 9,747,340 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G06F 16/172 Caching, prefetching or hoarding of files
• CPC Class Codes: G06F 16/2255 Hash tables
• CPC Class Codes: G06F 16/24552 Database cache management
• CPC Class Codes: G06F 16/9014 hash tables

Abstract

The described method and system enables a client at a branch office to retrieve data from a local hosted cache instead of an application server over a WAN to improve latency and reduce overall WAN traffic. A server at the data center may be adapted to provide either a list of hashes or the requested data based on whether a hosted cache system is enabled. A hosted cache at the client side may provide the data to the client based on the hashes. The hashes may be generated to provide a fingerprint of the data which may be used to index the data in an efficient manner.

Claims

1. A method of reducing bandwidth utilization of a network and improving latency of data retrieval over a network comprising:

connecting a client to a server via a first network;

connecting the client to a hosted cache via a second network, wherein the client is capable of communicating with the hosted cached via the second network independently of the first network;

transmitting a first request message from a client to the server over the first network, wherein the message contains a request for a set of data;

receiving at the client via the first network the requested set of data with a corresponding set of hashes or a set of hashes corresponding to the set of data without the set of data;

determining at the client whether the client receives the set of hashes with the set of data or receives the set of hashes without the set of data;

storing a copy of the set of data in the hosted cache via the second network when the client receives the set of hashes with the set of data; and

querying for the set of data by the client from the hosted cache via the second network based on the set of hashes, when the client receives the set of hashes without the set of data, wherein the hosted cache stores data indexed by hashes.

2. The method of claim 1, wherein the first network is an end-to-end secured network running one of a secured sockets layer protocol (SSL) or an IP Security (IPSec) protocol.

3. The method of claim 1, further wherein transmitting a first request message from the client to the server over the first network comprises transmitting a message that contains an indication that the client is enabled to utilize the hosted cache.

4. The method of claim 1, further comprising sending a request by the hosted cache for the client requested data to the server when the hosted cache does not contain the requested data.

5. The method of claim 1, further comprising receiving an indication from the hosted cache that the hosted cache does not contain data corresponding to the set of hashes and sending a second request for the requested data by the client to the server.

6. The method of claim 1, wherein the hosted cache stores an expiration parameter associated with each of the set of data containing an expiration value that indicates a period of validity for each data.

7. The method of claim 1, further comprising implementing the hosted cache as a distributed hash table stored across a plurality of clients connected via the second network.

8. The method of claim 1, wherein generating a set of hashes comprises generating the set of hashes based on an encryption algorithm, wherein the set of hashes are generated to be statistically unique for the data cached by the hosted cache.

9. The method of claim 1, further comprising verifying the set of data received from the hosted cache at the client by executing a hash function on the set of data and determining whether the hash function results in hashes that match the hashes used to query for the data.

10. A method of reducing bandwidth utilization of the network and improving latency of data retrieval over a network comprising:

receiving a request message from a client at a server over a network, wherein the message contains a request of the client for a set of data stored at the server;

generating a set of hashes using a first hash function for the set of data stored at the server, wherein each hash of the set of hashes represents a statistically unique fingerprint of each data of the set of data;

determining at the server whether the client is enabled to use a hosted cache, wherein the hosted cache indexes data based on hashes that are produced using the first hash function;

transmitting by the server to the client via the network the set of data and the corresponding generated set of hashes when the client is not enabled to use a hosted cache;

transmitting by the server to the client via the network the set of hashes without the set of data when the client is enabled to use a hosted cache.

11. The method of claim 10, further comprising providing the client a hash function that corresponds to a hash function used to produce the set of hashes for the set of data.

12. The method of claim 10, further comprising receiving a request message from the hosted cache at the server over a network, wherein the message contains a request of the hosted cache for the set of data stored at the server.

13. The method of claim 10, further comprising receiving a second request from the client for the same set of data wherein the client provides an indication that the hosted cache does not contain the set of data.

14. The method of claim 10, wherein determining whether the client is enables to use a hosted cache comprises performing a lookup of the client in a registry indicating which clients are enabled or reading an indication in the request message to determine whether the client is enabled.

15. A computing system for reducing latency on a wide area network including a set of computing devices the computing devices including a processor and a memory operatively coupled to the processor for storing instructions executable by the processor comprising:

a hosted cache adapted to store data indexed by a hash value;

a first network communicatively coupling a client and a server;

a second network communicatively coupling the client with a hosted cache, wherein the second network is independent of the first network and is configured to provide communications between the client and the hosted cached without using the first network;

a server adapted to transmit a set of data or a set of hashes corresponding to the set of data to a client in response to a client request via the first network; and

a client adapted to receive the set of hashes when the server transmits the set of hashes and to query the hosted cache via the second network for the set of data based on the received set of corresponding hashes.

16. The system of claim 15, wherein the client receives the set of data when the server transmits the set of data and wherein the client stores a copy of the set of data into the hosted cache by hash values.

17. The system of claim 15, wherein the hosted cache is adapted to send a request for the client requested data to the server when the hosted cache does not contain the requested data.

18. The system of claim 15, wherein the client is adapted to send a request for the set of data when the hosted cache does not contain the requested data.

19. The system of claim 15, wherein the server is adapted to generate the hashes using a hash function and wherein the client is adapted to verify data received from the hosted cache by hashing the data received from the hosted cache using the same hash function as the server.

20. The system of claim 15, wherein the server is further adapted to be a stateful server that tracks the set of data previously transmitted to a client and in response to further requests for the same set of data, transmits the set of hashes corresponding to the set of data instead of the set of data.